Installation for coating the inside of metal tubes



1967 H. ZOLLINGER 335K404 INSTALLATION FOR COATING THE INSIDE OF METALTUBES Filed Nov. 27, 1963 7 Sheets-Sheet 1 a? E k I N I Q A w C C) b C:0 q q I i \C g 1 E! If ISL/ BL; I c :51 Q o o Dec. 12, 1967 H. ZOLLINGER3,357,404

TALLATION FOR COATING THE INSIDE OF METAL TUBES INS '7 Sheets-Sheet 2Filed Nov. 27 1963 Dec. 12, 1967 H. ZOLLINGER 3,357,.404

INSTALLATION FOR COATING THE INSIDE OF METAL TUBES Filed NOV. 27, 1965'7 Sheets-Sheet I5 3,35'YAQ4 Dec. 12, 1967 H. ZOLLINGER INSTALLATION FORCOATING THE INSIDE OF METAL TUBES '7 Sheets-Sheet 4 Filed Nov. 27, 1963Dec. 12, 1967 H. ZOLLINGER 3,357,494;

INSTALLATION FOR COATING THE INSIDE OF METAL TUBES Filed Nov. 27, 1963'7 Sheets-Sheet 5) Dec. 12, 1967 H. ZOLLINGER INSTALLATION FOR COATINGTHE INSIDE OF METAL TUBES 7 Sheets-Sheet 6 Filed Nov. 27, 1963 FIG. IO.

INVENTOR HANS ZOLLINGER ATTORNEY.

1957 H. ZOLLINGER 3,35'ZAQ l- INSTALLATION FOR COATING THE INSIDE OFMETAL TUBES Filed Nov. 2'7, 1963 '7 Sheets-Sheet '7 INVENTOR HANSZOLLINGER ATTORNEY.

United States Patent 3,357,404 INSTALLATION FOR COATING THE INSIDE OFMETAL TUBES Hans Zollinger, Lausanne, Vaud, Switzerland, assignor toAutocalora S.A., Vevey, Switzerland, a corporation of Switzerland FiledNov. 27, 1963, Ser. No. 326,500 Claims priority, applicationSwitzerland, Dec. 21, 1962,

15,041/ 62; Aug. 31, 1963, 10,740/63 11 Claims. (Cl. 118--642) Thepresent invention relates to an installation for coating the inside ofmetal tubes.

Separate devices have previously been used for the various operationsassociated with glazing the inside of metal packing tubes, such asannealing the tube metal, glazing, and polymerization of the finishedglaze. This procedure has made any form of automation impossible.

It is an object of the present invention to obviate this disadvantage,and the present invention accordingly relates to an installation forcoating the inside of metal packaging tubes or other tubular articleswith a polymerized glaze, with a View to automating these variousoperations.

The installation according to the present invention comprises an endlesschain conveyor having supports for supporting the tubes and havingdisposed consecutively along its path: a device for loading tubes forglazing into the supports; an oven for annealing the metal of the tubes;at least one device for glazing the interior of the tubes; a glazepolymerization oven; and a device for unloading the glazed tubes;driving means provide a continuous advance of the conveyor; the glazingdevice is adapted to move between two positions spaced out along thepath of the conveyor; and coupling means periodically connect theglazing device to the conveyor for movement thereby between the said twopositions, return means being provided to return the glazing device tothe upstream position upon release of the said coupling means.

With these and other objects in view which will become apparent in thefollowing detailed description, the present invention will be clearlyunderstood in connection with the accompanying drawings, wherein:

FIGURE 1 is a general plan view of the installation;

FIGS. 2 and 3 are partial views, in elevation and plan, respectively, ofan endless-chain conveyor, with partial sections taken, in FIG. 2, alongthe lines 2-2 of FIG. 3, and in FIG. 3 along the lines 33 of FIG. 2;

FIGS. 4 and 5 are sections taken along the lines 4-4 and 55 respectivelyof FIG. 1, to an enlarged scale;

FIG. 6 is a section taken along the lines 6-6 of FIG. 3, to an enlargedscale;

FIG. 7 is a plan view of a coupling mechanism, the view being to anenlarged scale and looking in the direction of an arrow 7 in FIG. 5;

FIG. 8 illustrates a device for unloading tubes, the device being shownin various consecutive operative position;

FIG. 9 is a profile view of the device illustrated in FIG. 8 and lookingin the direction of arrows 9 therein;

FIG. 10 is a perspective front view of the glazing device; and

FIG. 11 is a perspective front view of the loading and unloading device.

Referring now to the drawings, and in particular to FIG. 1, theinstallation is for coating the inside of metal packing tubes with apolymerized glaze. The installation comprises an endless-chain conveyor1, which has arranged consecutively along its pathin the direction ofconveyor movement as indicated by an arrow A-a loading device 2 forloading tubes for glazing into supports borne by the conveyor, a furnaceor oven 3 for annealing the tube metal, a glazing device 4 for glazingthe inside of the tubes carried along by the conveyor, a furnace or oven5 for polymerizing the glaze, and an unloading device 6 for unloadingthe glazed tubes from the conveyor 1.

The conveyor 1, details of which are given in FIGS. 2 and 3, comprisesidentical carriages 7 articulated to one another by vertical pivot pins8. The carriages 7 each have a hollow bottom part or base part 9receiving running elements, which take the form for each carriage of twowheels 10 and a ball 11. At a considerable height above the runningplane of the running elements 10 and 11, the carriage has a horizontaldisc or tray or plate or the like 12 which is connected to the carriagebase part 9 by a central foot 13. The base part 9 and the plate 12 areof substantially the same width, but the foot 13 is much narrower. Edges14 of the plates 12 are straight and parallel and form carriage guiderails in a manner which will be described hereinafter.

The installation comprises a rigid frame 15 having four parallellongitudinal members 16 which extend over its whole length (FIG. 1). Thetwo ovens 3 and 5 rest on the members 16 and have plane bases 17 and 18,respec tively, which form running surfaces for the carriage runningmembers 10 and 11. The conveyor is guided by rotating guide posts 19borne by the oven bases 17 and 18 and the path of the conveyorcomprises, between the furnaces, two straight parts 20 and 21 borderedby rows of support rollers 22.

The rollers 22 are pivoted to blocks borne in each row by a longitudinalmember 23 secured to the nearby longitudinal member 16 by cross-pieces24. In the outer rows, the blocks 25 bearing the rollers are secured tothe longitudinal member 23, while in the inner rows the blocks 26hearing the rollers can move and can slide perpendicularly to theconveyor in stirrups 27 secured to the longitu dinal member 23 (FIG. 5and 6). The moving blocks 26 have lateral ribs received in grooves 28 inthe stirrups and each compnse a rod 29 extending through the stirrup andbearing an abutment 30 (FIG. 6). Resilient washers 31 threaded on therod 29 and placed between the stirrup 27 and the block 26 tend to forcethe associated roller 22 towards the conveyor 1.

The rollers 22 are formed with a peripheral groove 32 of V-shapedcross-section, and the side edges 14 of the carriage plates or the like12 are bevelled, as indicated by the numeral 33 in FIG. 6. I

As they leave the oven 3, and as can be seen in FIGS. 2 and 3, the edges14 of the plate 12 of the carriages 7 engage between the two rows ofrollers 22 bordering the path of the conveyor 1, the plate edges 14therefore forming guide rails which co-operate with the rotating rollers22 to support and guide the conveyor over the straight part 20 of itspath. Similar considerations apply to the straight part 21 of theconveyor path.

The carriages 7 are supported and guided between the two furnaces 3 and5 just by the rollers 22, there being no running surface in these partsof the conveyor path for the running elements 10 and 11 at the bottom ofthe carriages. Rollers 34 in FIGS. 2 and 3 facilitate the engagement ofthe plate 12 between the rollers 22, and the same are near enoughtogether for each plate 12 always to be in engagement with at least tworollers 22; the rollers 22 therefore oppose any longitudinal andtransverse tilting of the carriages 7.

The plate 12 of each carriage has spindles 35 rotatably mounted insleeves 36 rigidly secured to the plate 12; at their top end they have abasket 37 adapted to support a tube 38 placed vertically above theconveyor 1, in the position in FIG. 4.

The annealing oven 3 comprises a heating tunnel 39 having in its toppart three heating members 40 in the form of electric resistors, withgaps between them through which the tube baskets can pass. Protectivemeans are provided between the heating members 40 and the carriage chainto protect the same from the heat radiating from the top of the oven,and comprise two rows of 'bafiies 41 and 42 at different levels. The toprow 41 comprises a central horizontal bafiie 41a suspended between thetwo rows of baskets, and two side horizontal baffles 41b, 410 secured tothe tunnel side walls, the gap between the central bafiie and eachlateral bafiie being just enough for the vertical spindles 35 to passthrough. The bottom row 42 is formed by two lateral baffles 42a, 42bseparated by a gap narrower. than the plate or the like 12 and thecarriage base part 9, through which gap the central foot 13 connectingthe plate 12 to the base part 9 can pass.

The polymerization oven comprises a heating tunnel 43 similarly devisedto the tunnel 39 but with a number of resistors which can be varied tosuit the required polymerization temperature.

The installation comprises a driving motor 44 which provides acontinuous advance of the conveyor 1 (FIG. 1). The motor 44 drives via aspeed reducer 46 a gear 45 having a double toothed ring. Disposedbetween the gear 45 and an identical reversing wheel 47 is an endlesschain 48 whose runs extend parallel with the nearby part of theconveyor 1. The links of the chain 48 comprise parallel spindles 48a(FIG. 5) and lateral abutments 49 which project beyond the side surfaceof the carriagebasepart 9 in the path of the spindles 48a, so that thecarriages 7 which are opposite the chain 48 are driven thereby, so thatthe chain 48 advances the conveyor 1 continuously in the directionindicated by the arrow A in FIG. 1.

The glazing device 4 can be moved between two positions spaced out alongthe straight part 20 of the conveyor path, and coupling means shown inFIGS. 7 and connect the device 4 to the conveyor periodically formovement thereby between the two positions, return means being providedto return the glazing device 4 to its upstream position upon release ofthe coupling means.

For its displacement the glazing device 4 is mounted by way of feet 50on a movable solepiece 51 slidable on two circular cross-section guiderods 52 (FIGS. 7 and 10). The aforesaid coupling means comprise acoupling lever 53 articulated by a pivot 54 to the solepiece 51 andtending to be maintained by a spring 55 in the advanced angular positionillustrated in FIG. 7, in which position the lever 53 abuts at its rearend a pin 56, While its hook-shaped front end 57 is in the path of pins58 rigidly secured to the plates 12 of the carriages 7. A locking lever59 articulated by a pivot 60 to the solepiece 51 and ten-ding to bemaintained by a spring 61 in engagement with a pin 62, maintains thelever 53 in the angular position shown in FIG. 7, in which position themoving solepiece 51 is coupled with the conveyor carriage 7. Thesolepiece 51 moves with the conveyor 1 in the direction indicated by anarrow B in FIGS. 7 and 10 against the force of a return spring 63secured at one end to a foot (not shown) below the solepiece 51 and atthe other end to a bridge-piece 64 rigidly secured to the rods 52.

As the solepiece 51 moves to the right, the outer end 65 of the lockinglever 59 abuts an adjustable stop 66 secured by bolts or the like to alongitudinal member 67 of the frame of the installation. The stop 66causes the lever 59 to pivot against the force of the spring 61, so thatits end '68 rotates anticlockwise (FIGS. 7 and 10) and releases thecoupling lever 53. Because of the lateral position of the book 57relatively tothe pivot 54, and because of the resistance to advanceoffered by the return spring 63, the lever 53 disengages from the pin 58and the solepiece 51 is returned abruptly in the direction of the bridge64 by the return spring 63, while the conveyor 1 continues to move tothe right. Once the coupling lever 53 has disengaged from the pin 58,the spring 55 returns it to the advanced angular position illustrated inFIGS. 7 and 10', and the 4 locking lever 59 is returned to the lockedposition by the spring 61.

The reummeoentn rt v The return movement of the solepiece 51 isinterrupted when the coupling lever 53 strikes the following pin 58a,the solepiece 51 therefore moving with the conveyor from an upstreamposition, determined by the position of the pin 58 with which thecoupling lever 53 hooks up, to a downstream position determined by theabutment 66. The travel of the solepiece 51 is not always constant andcan adapt itself as required to variations in the spacings between thepins 58 and 58a.

The device 6 for unloading the glazed tubes can also move between twopositions spaced out along the straight part 21 of the conveyor path. Tothis end, the device 6 is borne by a moving solepiece 51' (FIG. 11) thesame as the solepiece 51 of the glazing device; an unloading couplingmeans 51" (comprising springs, levers, etc.), the same as the couplingmeans for the glazing device (and therefore not described in detail),periodically connects the solepiece 51' of the unloading device 6 to theconveyor 12, resilient return means 63 (the same as that for the returnof the glazing device), being provided to re turn the unloading deviceto its upstream position upon release of the coupling.

The unloading device 6, which is illustrated in FIGS. 8, 9 and 11,comprises,-on a stationary frame 69 having a slide 70 parallel with theconveyor path, a moving slideway 71 connected by an arm 71a, part ofwhich is shown in FIG. 9, to the moving solepiece 51' of the device 6.The slideway 71 bears a cylinder 72 pivotally mounted on pivots 73 andreceiving a piston 74. A rod 75 of the latter has at its bottom end agripper 76 adapted to seize the tube disposed in the tube basket 37 of asupport. The gripper 76 comprises a mandrel 76a disposed in the tubeend, and a moving part controlled by an electromagnet 86.

The coupling device is so devised that the slideway 71 moves past amoving basket 37 between an upstream position and a downstream position,in which position the axis C of the cylinder 72 respectively, takes upthe positions illustrated by the axes I and V in FIG. 8.

In position I, the piston 74 is maintained in its top position by aspring 77, and the gripper 76 is open and is in the top positionrepresented by the axis 1. In this up stream position, the chamberformed above the piston in the top part of the cylinder 72 communicates,through a duct 78 in one of the pivots of the cylinder and through aduct 79 in the slideway 71, with an exhaust port 80 pierced in the slide70. When the slideway 71 moves to the right (FIG. 8), such movementoccurring opposite a tube basket 37, the orifice of the duct 79 comesopposite a supply port 81 in the slide 70 and compressed air enters thecylinder 72 to force the piston 74 downwards against the force of thespring .77. The piston 74 then descends gradually, as denoted by II, andthe gripper 76 engages over. the tube end, as denoted by the referenceIII. In this position, a contact 82 at the top of the cylinder engageswith a stationary contact strip 83 to close an electric circuit toenergise an electromagnet 84 which operates the gripper 76 to close thesame on the tube edge. Shortly after position III, the air duct 79 comesopposite a second exhaust port 85 in the slide 70 and the air escapesfrom the cylinder 72 so that the gripper 76 which is closed on the tubereturns to the top position denoted by the reference IV and removes thetube from the basket 37.

From position I to position IV, the axis C of the cylinder 72 is in avertical position, and a roller 86. rigidly secured to an arm 87disposed on the side of the cylinder rests on a first flat part 88 of acam 89 secured to the frame 69, while a spring 90 which is compressedbetween the base of the slideway 71 and the top end of the cylinder 72keeps the roller 86 forced against the cam 89. When the cylinder 72moves slightly past the position IV, the roller 86 reaches a part 91near the end of the flat part 88 of the cam 89. As the advancingmovement continues, the

roller 86 engages with a second part 92 of the cam, such part beinginclined to the rear, so that the cylinder 72 pivots on its pivots 73and is inclined to the rear, as illustrated in FIG. 9, by the spring 90.This tilting movement disengages the contact 82 from the strip 83, sothat the gripper 76 opens and releases the tube which can drop into astationary receptacle 93 above which the tube has been brought. In itsrapid return movement the cylinder 72 does not have time to fill upcompletely, and it returns to position I opposite the next tube basket37.

The bases 17 and 18 of the annealing oven 3 and polymerisation oven 5comprise, on parts on the conveyor path corresponding inter alia to theheating tunnels 39 and 43 zones 94 where the sheet metal is pierced witha number of apertures communicating with an air distribution duct 95(FIGS. 1 and 4) disposed below such bases. The duct or trunking 95 acnbe supplied with fresh air by a fan 96, shown in FIG. 1, whose motor 97is supplied via a switch disposed in a casing 98; such switch is closedwhen the main driving motor 44 is energised and is driving theconveyor 1. It remains closed when the main motor 44 is stopped and mustbe opened individually for stopping the fan 96.

The cooling air supplied by the fan 96 and exhausting through theapertures in the zones 94 is injected into the hollow base parts 9 ofthe carriage 7, which are substantially open at the bottom, and thedistributing means thus formed ensure that the cooling air continues tobe distributed automatically should the conveyor 1 stop. This cooling ofthe carriages 7 means that the same can withstand a stoppage in thehottest part of their path without the need to switch off the heatingcurrent to the heating tunnels.

Some of the advantages of the installation disclosed are as follows:

In the annealing and polymerization ovens, the carriages of the endlessconveyor run on running elements placed at the bottom of the carriagesvery far away from the heating members, whereas in the loading, glazingand unloading stations, the carriages are guided and maintained via theedges of their plates or the like 12and much nearer the tube baskets37by rotating stationary elements which do not have to withstand thegreat heat of the ovens.

Because these two different guiding systems are used each on a part ofthe path of the conveyor, the same can pass inside the ovens and thetube baskets can be maintained in a predetermined position in theworking stations where it is necessary for the tubes to be positionedfairly accurately. There is therefore no disadvantage if the runningelements at the bottom of the carriages are relatively inaccurate, forthey can still operates correctly even in the absence of effectivelubrication. Also, since protective bafiles are provided in the heatingtunnels of the ovens, the chain can pas therethrough withoutoverheating. The tubes borne by the conveyor can therefore be moved fromone station to another and be processed in the various ways describedautomatically and without any waste of time.

As a variant, the installation can comprise more than one annealing ovenand more than one polymerization oven.

Since the glazing and unloading devices are driven by coupling meanswhich periodically couple their respective devices to the endlessconveyor, movements can be satisfactorily synchronised notwithstandingvariations in conveyor speed or in the gaps between the carriages 7.Good synchronisation is very important for the glazing station whereglaze guns 4' (FIG. descend into the moving tubes, and at the unloadingstation where, as already described, a gripper seizes the tubes.

As a variant, the grippers can be formed by extinsible mandrels whichare adapted to move vertically and which enter the tube insides veryaccurately to be secured in the tube necks.

Of course, the loading device can if required by adapted by a couplingmeans 51" to move along the conveyor path for movement thereby, forinstance, in the same manner as the unloading device (FIG. 11). A finalfeature is that the installation disclosed is also of use for glazingarticles other than packing tubes, for instance, metal boxes, covers orthe like, just by a simple change of shape of the tube baskets, hereinsuch being generally termed tubular articles or more briefly tubes.

While I have disclosed one embodiment of the present invention, it is tobe understood that this embodiment is given by example only and not in alimiting sense, the

scope of the present invention being determined by the objects and theclaims.

I claim:

1. Installation for coating the inside of tubular articles with apolymerized glaze comprising an endless-chain conveyor consisting ofcarriages; roller members disposed on the base of said carriages;articulation means connecting said carriages, supports on said carriagesfor supporting tubes disposed consecutively along the path of saidconveyor at the upper parts thereof so as to support tubes standingvertically above said conveyor; lateral guide rails for said carriages;a track for said conveyor along part of its path formed by a runningsurface for said roller members and over another part by rotatablesupport members on either side of the path engageable by the carriagelateral guide rails; at least one device for glazing the interior of thetubes; a glaze polymerization oven; an annealing oven, and a device forloading and unloading the tubes; driving means providing a continuousadvance of said conveyor; said glazing device being adapted to movebetween two positions spaced out along the path of said conveyor;coupling means periodically connecting said glazing device to saidconveyor for movement thereby between said two positions; and returnmeans to return said glazing device to the upstream position uponrelease of said coupling means.

2. The installation, as set forth in claim 1, wherein the ovencomprises; plane bases forming running surfaces for said carriage rollermembers; said tube loading, glazing and unloading devices being disposedon straight parts of the conveyor paths; and said rotatable supportmembers being engageable by lateral guide rails bordering the straightparts of the conveyor path.

3. The installation, as set forth in claim 1, wherein said rotatablesupport members oppose any lengthwise or transverse tilting of saidcarriages, whose rails are in engagement with such elements.

4. The installation, as set forth in claim 1, wherein said carriagescomprise; a hollow 'base part receiving said roller members; ahorizontal plate disposed at a considerable height'above the runningplane of the roller members, the lateral edges of such plate forming thesaid carriage guide rails; and a central foot which is much narrowerthan said plate and than the carriage base part connecting said plate tosaid hollow base part.

5. The installation, as set forth in claim 1, wherein said carriagescomprise; a hollow base part receiving said roller members; a horizontalplate disposed at a considerable height above the running plane of therunning elements, the lateral edges of said plate forming said carriageguide rails; and a central foot which is much narrower than said plateand than the carriage base part connecting said plate to said hollowbase part, and wherein the bases of said ovens are formed to defineperforations through which cooling air can be injected into said hollowbase part of said carriages when the same are in said ovens; and thecooling air is distributed automatically by distributing means in theevent of the conveyor stopping.

6. Installation for coating the inside of tubular articles with apolymerized glaze, comprising an endless chain conveyor consisting ofcarriages; roller members disposed on the base of said carriages;articulation means connecting said carriages, supports on said carriagesfor supporting tubes disposed consecutively along the path of saidconveyor at the upper parts thereof, so as to support tubes standingvertically above said conveyor; lateral guide rails for said carriages;a track for said conveyor along part of its path formed by a runningsurface for said roller members and over another part by rotatablesupport members on either side of the path engageable by the carriagelateral guide rails; at least one device for glazing the interior of thetubes; a glaze polymerization oven; an annealing ovenand a device forunloading the glazed tubes; driving means provide a continuous advanceof said conveyor; said glazing device being adapted to move between twopositions spaced along the path of said conveyor; coupling meansperiodically connecting said glazing device to said conveyor formovement thereby between the said two positions; and return means toreturn said glazing device to the upstream position upon release of saidcoupling means, wherein the annealing and polymerization ovens compriseheating members disposed in the top part of heating tunnels in saidovens; and protective means provided between said heating members andsaid carriages to protect the same from the heat radiating from the toppar-t of the tunnels.

7. The installation, as set forth in claim 6, wherein the protectivemeans comprise baflies having surfaces which reflect the heat upwardsinto the top part of the heating tunnels.

8. The installation for coating the inside of tubular articles with apolymerized glaze, comprising an endless chain conveyor consisting ofcarriages; roller members disposed on the base of said carriages;articulation means connecting said carriages, supports on said carriagesfor supporting tubes disposed consecutively along the path of saidconveyor at the upper parts thereof, so as to support tubes standingvertically above said conveyor; lateral guide rails for said carriages;a track for said conveyor along part of its path formed by a runningsurface for said roller members and over another part by rotatablesupport members on either side of the path engageable by the carriagelateral guide rails; at least one device for glazing the interior of thetubes; a glaze polymerization oven; an annealing oven, and a device forunloading the glazed tubes; driving means providing a continuous advanceof said conveyor; said glazing device being adapted to move between twopositions spaced along the path of said conveyor; coupling meansperiodically connecting said glazing device to said conveyor formovement thereby between said two positions; and return means to returnsaid glazing device to the upstream position upon release of saidcoupling means, wherein said annealing and polymerization ovens compriseheating members disposed in the top part of heating tunnels in saidovens; and protective means provided between said heating members "andsaid carriages to protect the same from the heat radiating from the toppart of the tunnels, wherein said carriages comprise; a hollow base partreceiving said roller members; a horizontal plate disposed at aconsiderable height above the running plane of the running elements, thelateral edges of such plate forming said carriage guide rails; and acentral foot which is much narrower than said plate and than saidcarriage base part connecting said plate to said hollow base part.

9. The installation, as set'forth in claim 8, wherein said tunnels havelateral bafiies which are disposed opposite one another and which areseparated from One another by a gap narrower than said plates and theconveyor carriage base parts, such gap serving as a passage for thecentral foot which connects said carriage base parts to said plates.

10. The installation, as set forth in claim 8, wherein each conveyorcarriage plate has at least two rows of article supports; and a centralhorizontal bafiie is suspended between such rows and two horizontallateral baffles are secured to the tunnel side walls, the distancebetween said central bafile and each lateral bafiie being just enough toallow vertical rods which bear said supports to pass through.

11. Installation for coating the inside of tubular articles with apolymerized glaze, comprising; an endless chain conveyor; supports forsupporting tubes disposed consecutively along the path of said conveyor;a device for loading tubes for glazing into said supports; an oven forannealing the metal of the tubes; at least one device for glazing theinterior of said tubes; a glaze polymerization oven; a device forunloading the glazed tubes; driving means for providing a continuousadvance of said conveyor; said glazing device being adapted to movebetween two glazing positions spaced out along the path of saidconveyor; glazing coupling means periodically connecting said glazingdevice to said conveyor for movement thereby between said two glazingpositions; and return means to return said glazing device to theupstream position upon release of the said glazing coupling means; saiddevice for unloading the glazed tubes adapted to be moved between twounloading positions spaced out along the path of said conveyor andcomprising; unloading coupling means periodically connecting saidunloading device to said conveyor for movement thereby between said twounloading positions; and return means to return said unloading deviceinto the upstream position upon release of said unloading couplingmeans.

References Cited UNITED STATES PATENTS 1,055,320 3/1913 Claussen et a1.118-317 X 1,271,027 7/1918 Gail 1l8-58 2,069,845 2/1937 Paasche.

2,333,557 11/1943 Fischer.

2,547,884 4/1951 Paasche 1l8-32l X 2,611,493 9/ 1952 Nordquist.

2,660,978 12/1953 Dyne et a1 1l83 17 X 2,676,895 4/1954 Russel 1l83l8 X2,781,738 2/1957 Paasche l1832l X DANIEL BLUM, Primary Examiner.

1. INSTALLATION FOR COATING THE INSIDE OF TUBULAR ARTICLES WITH APOLYMERIZED GLAZE COMPRISING AN ENDLESS-CHAIN CONVEYOR CONSISTING OFCARRIAGES; ROLLER MEMBERS DISPOSED ON THE BASE OF SAID CARRIAGES;ARTICULATION MEANS CONNECTING SAID CARRIAGES, SUPPORTS ON SAID CARRIAGESFOR SUPPORTING TUBES DISPOSED CONSECUTIVELY ALONG THE PATH OF SAIDCONVEYOR AT THE UPPER PARTS THEROF SO AS TO SUPPORT TUBES STANDINGVERTICALLY ABOVE SAID CONVEYOR; LATERAL GUIDE RAILS FOR SAID CARRIAGES;A TRACK FOR SAID CONVEYOR ALONG PART OF ITS PATH FORMED BY A RUNNINGSURFACE FOR SAID ROLLER MEMBERS AND OVER ANOTHER PART BY ROTATABLESUPPORT MEMBERS ON EITHER SIDE OF THE PATH BY ENGAGEABLE BY THE CARRIAGELATERAL GUIDE RAILS; AT LEAST ONE DEVICE FOR GLAZING THE INTERIOR OF THETUBES; A GLAZE POLYMERIZATION OVERN; AN ANNEALING OVEN, AND A DEVICE FORLOADING AND UNLOADING THE TUBES; DRIVING MEANS PROVIDING A CONTINUOUSADVANCE OF SAID CONVEYOR; SAID GLAZING DEVICE BEING ADAPTED TO MOVEBETWEEN TWO POSITIONS SPACED OUT ALONG THE PATH OF SAID CONVEYOR;COUPLING MEANS PERIODICALLY CONNECTING SAID GLAZING DEVICE TO SAIDCONVEYOR FOR MOVEMENT THEREBY BETWEEN SAID TWO POSITIONS, AND RETURNMEANS TO RETURN SAID GLAZING DEVICE TO THE UPSTREAM POSTIONS UPONRELEASE OF SAID COUPLING MEANS.